Method of making weatherproof nails



G. E. DICKSON. METHOD OF MAKING WEATHERPROOF NAILS.

APPLICATION FILED mus 19 9 1,342,742. PatentedJune8,1920.

PATENT OFFICE.

GEORGE E. DICKSON, OF CHICAGO, ILLINOIS.

METHOD OF MAKING WEATHERPROOF NAILS.

Specification of Letters Patent.

Patented June 8, 1920.

5, 1919. Serial No. 294,753.

To all whom it may concern: 1

Be it known that I, GEORGE E. DICKSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain and useful Improvements in Methods of Making Weatherproof Nails, of which the following is a specification.

This is a division of my application Serial No. 190,071, filed September 6, 1917, allowed February 13, 1919.

The invention relates to weatherproof nails which have,soft metal caps and its object is to provide an improved method for making such nails by reducing the quantity of metal required for making the cap and distributing this metal and applying it so as to provide a strong and substantial cap securely anchored to the shank of the nail and with the metal disposed and distributed to meet all requirements for a nail of this character, whereby a superior weatherproof nail is produced at a reduced cost of manufacture.

Figure 1 is a view in perspective of a nail constructed in accordance with my invention.

Fig. 2 is an elevation of a nail with the metal cap in section.

Fig. 3 is a sectional view through a die and punch adapted for use in carrying out my invention and illustrating the nail and soft metal at the commencement of the operation, and

Fig. 41 is a "similar view illustrating the nail and soft metal cap at the conclusion of the operation.

Ordinary nails are not adapted for use in securing sheet metal .to supporting structures in exposed situations for the reason that moisture is permitted to enter about the shank of the nail andcorrode the under side of the sheet metal. The nail itself also corrodes rapidly and soon becomes useless. It has heretofore been suggested to inclose the head of the nail in a soft metal cap. Such nails have been manufactured by casting a soft metal cap about the head of the nail, but these nails have not. been entirely satisfactory because the soft metal is not properly distributed to produce the best results in practical use. Moreover the cost of such nails is relatively high because a considerable quantity of lead must be used to insure that the metal will flow during the casting operation and because of the high percentage of waste which results from this method.

Such'nails have a large proportion of the lead above the head of the nail, and when the nail is driven the head is forced upwardly through the soft metal causing the cap to become loose. The soft metal above the head of the nail is ineffective except as it affords protection against corrosion, and consequently a considerable quantity of the lead is wasted.

By my improved method I am enabled to provide a nail which overcomes all of the disadvantages referred to and which requires only about one half of the metal heretofore employed in making the soft metal cap whereby the cost of manufacture is materially reduced and the metal is distributed so that the efficiency of the cap is greatly increased.

Referring to the drawing, 5 indicates the shank of a nail which may be of ordinary wire type having a head 6 of any desired shape but preferably as shown in the drawing. The head 6 is inclosed in a cap 7 which may be of any suitable soft metal but is preferably formed of lead. The top 8 of the cap' is rounded or spherical in form, and the under side 9 is slightly conical in form so that the edge 10 first engages the sheet metal when the nail is driven.

l have discovered that by the use of a herein described punch and die the soft metal cap 7 may be secured to the head of the nail in a single operation and without heating the'soft metal. In carrying out my invention, I employ a die 11 mounted in a suitable support 12 and having a chamber 1. The die is provided with a central opening 13 to receive the shank 5 of the nail. The bottom 14 of the die chamber slopes away from the opening 13 and corresponds in form to the conical bottom 9 of the soft metal cap 7. A mass 15 containing the required quantity of soft metal to make the head is dropped into the die chamber as indicated in Fig. 3. For convenience in handling it is desirable to use a spherical mass as shown, although the shapeof the mass is of no importance whatever. A punch 16snugly fits the die chamber and is provided with a depression 17 in its end to form the top of the soft metal cap 7. lVhen if Original application filed September 6, 1917, Serial No. 190,071. Divided and this application filed May the punch 16 is forced into the die chamber at a suitable pressure, the mass 15 is distributed to assume the form indicated in Fig. 4 of the drawing, the metal flowing under the head 6 of the nail to firmly lock the cap to the head. The nail is then withdrawn from the die and the, operation is repeated, v

My invention is adapted to the production of weatherproof nails embodying soft metal caps with the minimum application of power and with great rapidity. Each nail is perfect, and need not be inspected before shipment as is necessary with nails having the head cast thereon. I am enabled to make nails with a minimum predetermined standard quantity of soft metal, all of which is essential to the successful performance of the desired function. None of the soft metal is wasted as in other forms of weatherproof nails.

In using the nail the shank 5 is forced through the sheet metal and the nail is driven home until the edge lOengages the sheet metal. v The cap is flattened slightly and the edge 10 engages the sheet metal throughout its circumference thus effectively sealing the opening through which the shank of the nail passes. Thus entrance of moisture and consequent corrosion is prevented.

The head of the nail is protected by the layer of soft metal which overlies it.

I claim:

The method of applying a soft metal cap to the head of a nail to make a weatherproof nail which consists in providing a die with a chamber therein having a diameter substantially equal to that of the cap to be applied and open at one end and having a passage communicating with its other end, inserting a nail in said passage to close communication between the chamber and said passage, said nail having its head arranged in said chamber with its top, edge and bottom free, inserting a mass of cold soft metal in said chamber above the head of the nail, said mass being suflicientto form the cap, and then subjecting said mass to pressure by introducing a punch through the open end of the chamber to cause the entire mass of metal to flow over the top and about the edge and under the bottom of said head to form in one operation a complete cap consisting of all of said mass of metal and locked to the head of the nail.

GEORGE E. DICKSON.

\Vitnesses:

\VM. 0. BELT, M. A. KIDDIE. 

